With commit ef6000b4c6 ("Disable the __builtin_return_address()
warning globally after all)" the kernel does not warn at all again if
__builtin_return_address(n) is called with n > 0.
Besides the fact that this was a false warning on s390 anyway, due to
the always present backchain, we can now revert commit 5606330627
("s390/dumpstack: implement and use return_address()") again, to
simplify the code again.
After all I shouldn't have had return_address() implememted at all to
workaround this issue. So get rid of this again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>